When Shaytaan was rejected and thrown out of the heavens he said to Allah Ta’ala: “I swear that since you have sent me astray, I will lie in wait for them on the straight path. Then I will Approach them (to mislead them) from the front, from behind them, from their right and from their left.
The most treacherous attack of shaytaan is that he presents an irreligious deed as a religious one, so that one engages in it as an act of righteousness and hopes to get rewarded for it. Since the person performs it as a religious act, there is no likelihood of him making Tawba. If someone is addicted to obvious sins like adultery and theft there is a possibility that he may make Tawba and give them up. However, if someone is doing something wrong under the impression that it is a religious duty, then the question of him making Tawba does not arise. Rather he will get more involved in it day by day. This explains the words of shaytaan: “I involved them in sins but they frustrated my efforts through Zikr, Tawba and Istighfaar, thereupon I confused then in such a manner that it was then impossible for them to escape.”
Imam Ghazali (Rahmatullahi Alayh) has reported from Hasan Basri (Rahmatullahi Alayh), a narrative that shaytaan says: “I presented sinful deeds in an attractive form to the muslims but they nullified my efforts through Istighfaar, then I presented before them vices in the garbs of virtues, thus leaving no chance for Istighfaar.”
Lesson: It is essential that in all matters of Deen, guidance be sought from the way of Life of Rasulullah (Sallallahu Alayhi Wasallam) and of His Sahabah (Radiyallahu Anhum). Acting contrary to the way of Rasulullah (Sallallahu Alayhi Wasallam) involves a person in sin.